Nodal Analysis of Circuits Containing Current Conveyors

A special method of the nodal analysis of the circuits containing several types of the multiport current conveyors is presented in this paper. The method is based on the given regular and homogeneous models of the irregular current conveyors by the gyrators. Then a diakoptic solving and modification of the inversion of the admittance matrix is applie

Особливості розв’язання зворотної задачі імпедансної томографії методом зон провідності

The comparison of the iterative process convergence for the EIT inverse problem solving by classical Newton-Raphson method, regularization method by A. Tyhonov and asymmetric current source connection to zones phantom is carried out. Ill-conditionality of the derivatives matrix is shown. It leads to very big errors. The regularization method by A. Tyhonov gives satisfactory results at any position of zones phantom relatively current source connection. Chosen methods for the inverse problem are programmed easy and are convenient in practice, because of their usage with zones conductivities method.Проведено сравнение сходимости итерационной процедуры решения обратной задачи импедансной томографии классическим методом Ньютона – Рафсона, методом регуляризации по А.Н. Тихонову и методом асимметричного подключения источника тока к зонному фантому. Показано плохую обусловленность матрицы производных, что приводит к непозволительно высоким погрешностям. При любом положении зонного фантома относительно источника тока регуляризация по Тихонову даёт удовлетворительный результат. Избранные для решения обратной задачи методы легко программируются и удобны на практике благодаря их использованию совместно с методом зон проводимости.Проведено порівняння сходимості ітераційної процедури розв’язання зворотної задачі імпедансної томографії класичним методом Ньютона-Рафсона, методом регуляризації за А.Н. Тихоновим та методом асиметричного підключення джерела струму до зонного фантома. Показано погану зумовленість матриці похідних, що приводить до дуже великих похибок. При довільному розташуванні зонного фантома відносно джерела струму регуляризація за Тихоновим дає задовільні результати. Обрані для розв’язання зворотної задачі методи легко програмуються і зручні на практиці завдяки їх використанню разом із методом зон провідності

Modern look to the risk factors and prevention of cervical cancer

An analytical review of research in the field of epidemiology and carcinogenesis of cervical cancer and measures and technologies for the prevention of this form of cancer has been carried out. There are considered data on the main proven risk factors for cervical cancer, which are as follows: certain characteristics of sexual behavior and reproductive history, sexual infections and infection with human papillomavirus (HPV), tobacco smoking and some other lifestyle characteristics. According to world reference data the analysis of existing methods of cervical cancer prevention including sanitation, HPV vaccination and various types of screening for cervical cancer was conducted. Data on the significance, effectiveness and availability of various preventive technologies are presented

Personificated use of radiation therapy for the vulvar cancer patients

Vulvar cancer is a rare malignant tumor, accounting for 3–8% of the total incidence of malignant tumors of the female reproductive system. However, in the structure of mortality, this pathology ranks fourth after cancer of the cervix, uterine body and ovaries and amounts to 18.2%. Features of the anatomical structure of the external genital organs of a woman with a developed system of blood and lymphatic vessels cause an aggressive course, a tendency to metastasis and rapid growth of a tumor of this localization. Prospects for the timely diagnosis of vulvar cancer and vaginal tumors are directly related to an increase in literacy and oncological alertness of staff in general medical institutions, in the implementation of which not only the detection of the disease in the early stages, but also work with women from risk groups to refer them to further examination and, if necessary, for treatment in a specialized institution. High mortality from these diseases is associated with the appeal of women at the late stages of the development of the oncological process, as well as with the insufficient effectiveness of the therapy, which necessitates the development of research in this area